docs: def gen_experiment_id(n=10):
      """Generate a random string with n characters.
  
      Parameters
      ----------
      n : int
          The length of the string to be generated.
  
      Returns
      -------
      :obj:`str`
          A string with only alphabetic characters. 
      """
      chrs = 'abcdefghijklmnopqrstuvwxyz'
      inds = np.random.randint(0,len(chrs), size=n)
      return ''.join([chrs[i] for i in inds])